So what explanation could there be for why Romans would be included among the executioners of Jesus IF in the original narrative it was exclusively a Jewish affair?
The Gospel of Mark is all about balancing Jews and Gentiles. Kelber demonstrates this the most graphically with his “Mark’s Story of Jesus” (1979). Mark 4.35-8.21 is divided into 2 ethnic halves that are united in the end via the symbol of the lake (p.41). Compare the feeding of the 5000 (jewish) and the feeding of the 4000 (gentile) — not an accidental or silly editorial oversight when one notes 8.1 originally translates as “again” thus indicating a deliberate original repetition.
If Mark is a Pauline gospel (which I like to think it is despite having some unresolved questions re this hypothesis, although they MAY be ‘explained’ as later redactions….) then it surely becomes inevitable that it must involve BOTH jews and gentiles in culpability for the death of Jesus. Paul, we know, implicates BOTH Jews and Gentiles as incurring guilt and in equal need of salvation over the Saviour sent from God.
If there is anything to this hypothesis then it throws into question the traditional academic postulation of some single trajectory from Q or Mark to whatever …. it would imply that the differences are fundamentally the consequence of a dialogue or rivalry between the different gospel authors, not an organic evolutionary trajectory.
I have often wondered about the connection between “Mark” and “Marc”ion — and am encouraged to read in Robert M. Price’s “The Pre-Nicene New Testament” that I am not alone with this question (p.70).